The invention relates to a well-treating process for increasing the rate at which fluid can be produced from an oil-productive relatively unconsolidated siliceous reservoir. More particularly, the invention relates to a reservoir acidizing process in which (a) the mechanical effects of injecting and subsequently producing reservoir treating fluids are limited by using relatively slow rates of fluid inflow and outflow and slow rates of change in the flow rates, and (b) the chemical effects of the treating fluids are limited by using fluids having relatively low concentrations and/or volumes.
The need for stimulating subterranean reservoirs, in order to increase their productivity, has been known and worked on substantially as long as oil has been produced. The stimulation problems are complex, particularly in respect to relatively unconsolidated siliceous reservoirs that contain clay. Numerous proposals and discussions have been published, particularly with respect to what kind of chemicals should be injected and which of the previously proposed treatments were actually beneficial.